Aqueous coating systems in which carboxy-functional copolymers containing hydroxy groups are dispersed in water with the aid of water miscible organic solvent and a volatile amine and cured by the presence of a water soluble or water dispersible aminoplast or phenoplast curing agent are known and have various uses. Thus, they may be used directly as coatings (applied by spray roller, etc.) or they may be diluted and electrodeposited at the anode of a unidirectional electrical system. It is desired to speed the cure and/or lower curing temperature. It is also desired to improve the properties of the cured coatings, such as salt spray resistance, detergent resistance, abrasion resistance, hardness and adhesion to various substrates (especially untreated steel and aluminum).